An important question every author should consider is ‘Does your character think like you?’ It’s okay if they do, it’s okay if they don’t. What’s not okay, is if they think like you but are of a different gender. Hear me out.
Male brains are wired differently than female ones. The changes go back to when our society consisted of hunters and gatherers. Men needed strength, a sense of direction, and a single-minded focus to hunt. Women needed to multitask, create safe havens, and communicate to keep children and families alive. As such, men developed a thicker right hemisphere which controls large muscle masses, and use their hippocampus more for their sense of direction. They have fewer dendrite connections.
These characteristics make men stronger, allow them to find things unerringly, and create a single line of thought. Women can transfer information from one side of their brain to the other faster, possess more dendrite connections, have a larger limbic system that controls emotion, and store language in both sides of their brains. These traits give women the ability to do several things at once very well, to consider several options simultaneously, nest and nurture, and to communicate in multiple ways.
A male and female might arrive at the same solution, but their brains will take different paths to get there. I sometimes answer a question that my husband is thinking of shortly before he asks it. Based on our conversation and the information around us, I know where his mind will go because he thinks in a straight line. He is astounded, every time.
When a character comes across as not true, focus on their thoughts. They may say or think things that make sense but somehow don’t sound right. One of the reasons for the discrepancy is that a male says something feminine, or a female says something masculine. For example, usually when a man complains he wants a solution. Generally, when a woman complains she wants sympathy. Many a fight can occur because the wrong response is offered when a person is upset. Watch the responses of your characters to make sure they respond true to their brains.
A word of caution: Take these ideas as suggestions and not hard and fast rules. Look for overall tendencies and remember that all tendencies do not apply to all people.